Application of a minimal glacier model to Hansbreen, Svalbard

Hansbreen is a well studied tidewater glacier in the southwestern part of Svalbard, currently about 16 km long. Since the end of the 19th century it has been retreating over a distance of 2.7 km. In this paper the global dynamics of Hansbreen are studied with a minimal glacier model, in which the ic...

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Main Authors: J. Oerlemans, J. Jania, L. Kolondra
Format: Article
Language:English
Published: Copernicus Publications 2011-01-01
Series:The Cryosphere
Online Access:http://www.the-cryosphere.net/5/1/2011/tc-5-1-2011.pdf
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spelling doaj-243dde4db94340b28ac8efe52bb10ce32020-11-24T23:10:15ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242011-01-015111110.5194/tc-5-1-2011Application of a minimal glacier model to Hansbreen, SvalbardJ. OerlemansJ. JaniaL. KolondraHansbreen is a well studied tidewater glacier in the southwestern part of Svalbard, currently about 16 km long. Since the end of the 19th century it has been retreating over a distance of 2.7 km. In this paper the global dynamics of Hansbreen are studied with a minimal glacier model, in which the ice mechanics are strongly parameterised and a simple law for iceberg calving is used. The model is calibrated by reconstructing a climate history in such a way that observed and simulated glacier length match. In addition, the calving law is tuned to reproduce the observed mean calving flux for the period 2000–2008. <br><br> Equilibrium states are studied for a wide range of values of the equilibrium line altitude. The dynamics of the glacier are strongly nonlinear. The height-mass balance feedback and the water depth-calving flux feedback give rise to cusp catastrophes in the system. <br><br> For the present climatic conditions Hansbreen cannot survive. Depending on the imposed climate change scenario, in AD 2100 Hansbreen is predicted to have a length between 10 and 12 km. The corresponding decrease in ice volume (relative to the volume in AD 2000) is 45 to 65%. <br><br> Finally the late-Holocene history of Hansbreen is considered. We quote evidence from dated peat samples that Hansbreen did not exist during the Holocene Climatic Optimum. We speculate that at the end of the mid-Holocene Climatic Optimum Hansbreen could advance because the glacier bed was at least 50 m higher than today, and because the tributary glaciers on the western side may have supplied a significant amount of mass to the main stream. The excavation of the overdeepening and the formation of the shoal at the glacier terminus probably took place during the Little Ice Age.http://www.the-cryosphere.net/5/1/2011/tc-5-1-2011.pdf
collection DOAJ
language English
format Article
sources DOAJ
author J. Oerlemans
J. Jania
L. Kolondra
spellingShingle J. Oerlemans
J. Jania
L. Kolondra
Application of a minimal glacier model to Hansbreen, Svalbard
The Cryosphere
author_facet J. Oerlemans
J. Jania
L. Kolondra
author_sort J. Oerlemans
title Application of a minimal glacier model to Hansbreen, Svalbard
title_short Application of a minimal glacier model to Hansbreen, Svalbard
title_full Application of a minimal glacier model to Hansbreen, Svalbard
title_fullStr Application of a minimal glacier model to Hansbreen, Svalbard
title_full_unstemmed Application of a minimal glacier model to Hansbreen, Svalbard
title_sort application of a minimal glacier model to hansbreen, svalbard
publisher Copernicus Publications
series The Cryosphere
issn 1994-0416
1994-0424
publishDate 2011-01-01
description Hansbreen is a well studied tidewater glacier in the southwestern part of Svalbard, currently about 16 km long. Since the end of the 19th century it has been retreating over a distance of 2.7 km. In this paper the global dynamics of Hansbreen are studied with a minimal glacier model, in which the ice mechanics are strongly parameterised and a simple law for iceberg calving is used. The model is calibrated by reconstructing a climate history in such a way that observed and simulated glacier length match. In addition, the calving law is tuned to reproduce the observed mean calving flux for the period 2000–2008. <br><br> Equilibrium states are studied for a wide range of values of the equilibrium line altitude. The dynamics of the glacier are strongly nonlinear. The height-mass balance feedback and the water depth-calving flux feedback give rise to cusp catastrophes in the system. <br><br> For the present climatic conditions Hansbreen cannot survive. Depending on the imposed climate change scenario, in AD 2100 Hansbreen is predicted to have a length between 10 and 12 km. The corresponding decrease in ice volume (relative to the volume in AD 2000) is 45 to 65%. <br><br> Finally the late-Holocene history of Hansbreen is considered. We quote evidence from dated peat samples that Hansbreen did not exist during the Holocene Climatic Optimum. We speculate that at the end of the mid-Holocene Climatic Optimum Hansbreen could advance because the glacier bed was at least 50 m higher than today, and because the tributary glaciers on the western side may have supplied a significant amount of mass to the main stream. The excavation of the overdeepening and the formation of the shoal at the glacier terminus probably took place during the Little Ice Age.
url http://www.the-cryosphere.net/5/1/2011/tc-5-1-2011.pdf
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